ASTM D7346-15(2021)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D7346 − 15 (Reapproved 2021)
Standard Test Method for
No Flow Point and Pour Point of Petroleum Products and
Liquid Fuels
This standard is issued under the fixed designation D7346; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D4177 Practice for Automatic Sampling of Petroleum and
Petroleum Products
1.1 Thistestmethodcoversthedeterminationofthenoflow
D6300 Practice for Determination of Precision and Bias
point and pour point of petroleum products, liquid fuels,
Data for Use in Test Methods for Petroleum Products,
biodiesel, and biodiesel blends using an automatic instrument.
Liquid Fuels, and Lubricants
1.2 The measuring range of the apparatus is from –95 °C to
D6708 Practice for StatisticalAssessment and Improvement
45 °C, however the precision statements were derived only
of Expected Agreement Between Two Test Methods that
from samples with no flow point temperatures from –77 °C to
Purport to Measure the Same Property of a Material
+2 °C and samples with pour point in the temperature range of
–58 °C to +12 °C.
3. Terminology
1.3 Pour point results from this test method can be reported
3.1 Definitions:
at 1 °C or 3 °C intervals.
3.1.1 pour point, n—in petroleum products, the lowest
temperature at which movement of the test specimen is
1.4 The values stated in SI units are to be regarded as
observed under the prescribed conditions of the test.
standard. No other units of measurement are included in this
standard.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 no-flow point, n—in petroleum products, the tempera-
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the ture of the test specimen at which a wax crystal structure
formation or viscosity increase, or both, is sufficient to impede
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter- movement of the surface of the test specimen under the
conditions of the test.
mine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accor- 3.2.1.1 Discussion—The no-flow point occurs when, upon
dance with internationally recognized principles on standard- cooling, the formation of wax crystal structures or viscosity
ization established in the Decision on Principles for the increase, or both, have progressed to the point where the
Development of International Standards, Guides and Recom- applied observation device no longer detects movement under
mendations issued by the World Trade Organization Technical the conditions of the test.
Barriers to Trade (TBT) Committee.
4. Summary of Test Method
2. Referenced Documents
4.1 After inserting the test specimen into the automatic no
2.1 ASTM Standards: flow point apparatus and initiating the program, the test
D97 Test Method for Pour Point of Petroleum Products specimen is heated, if necessary, to a starting temperature and
D4057 Practice for Manual Sampling of Petroleum and then cooled by prescribed rates. The test specimen is continu-
Petroleum Products ously tested for flow characteristics by continuously monitor-
ing the air pressure variation inside the test specimen vial.
When the specimen is still fluid, its movement will partially
This test method is under the jurisdiction of ASTM Committee D02 on
compensateforthereductioninairpressureinthetestchamber
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
above the test specimen surface. At some temperature the
Subcommittee D02.07 on Flow Properties.
pressure measuring system detects a pressure decrease due to
Current edition approved April 1, 2021. Published May 2021. Originally
incapability of the test specimen to flow caused by a crystal
approved in 2007. Last previous edition approved in 2015 as D7346 – 15. DOI:
10.1520/D7346-15R21.
structure formation in the specimen or its viscosity increase, or
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
both. This temperature is recorded as no flow point with a
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
resolution of 0.1 °C. The pour point is recorded by rounding
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. the no flow point temperature to either the next warmer 1 °C
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7346 − 15 (2021)
interval or 3 °C interval. The test specimen is then reheated to placed inside of bath, for use in effectively dissipating and
allow for removal from the test chamber. removing air or gas bubbles that can be entrained in viscous
sample types prior to analysis. It is permissible to use ultra-
5. Significance and Use
sonic baths with operating frequencies and power outputs
outside this range, however it is the responsibility of the
5.1 The no flow point of a petroleum product is an index of
laboratory to conduct a data comparison study to confirm that
thelowesttemperatureofitsutilityforsomeapplications.Flow
results determined with and without the use of such ultrasonic
characteristics, such as no flow point, can be critical for the
baths does not materially impact results.
proper operation of lubricating systems, fuel systems, and
pipeline operations.
7. Reagents and Materials
5.2 Petroleum blending operations require precise measure-
7.1 Specimen Vial—Disposable, clear glass cylinder with
ment of the no flow point.
closed flat bottom, 1 mL capacity.
5.3 This test method can determine the temperature of the
Dimensions:
test specimen with a resolution of 0.1 °C at which either
Outer diameter: 8.0 mm to 8.3 mm
crystals have formed or viscosity has increased sufficiently, or
Wall thickness: 0.75 mm to 0.85 mm
both, to impede flow of the petroleum product. Outer length: 39.25 mm to 40.25 mm
NOTE 1—Standard NWV type vial was found suitable for the applica-
5.4 The pour point of a petroleum product is an index of the
tion.
lowest temperature of its utility for certain applications. Flow
characteristics, like pour point, can be critical for the correct
7.2 Specimen Vial Stopper—Disposable, proprietary de-
operation of lubricating oil systems, fuel systems, and pipeline
signed for use in this apparatus.
operations.
7.3 Micropipette—Capable of delivering 0.5 mL 6 0.1 mL
5.5 Petroleum blending operations require precise measure-
of sample. Positive displacement type micropipette with cap-
ment of the pour point.
illary piston is preferred for use. Air-displacement type mi-
cropipettes are not recommended for viscous samples.
5.6 Pour point results from this test method can be reported
at either 1 °C or 3 °C intervals.
8. Sampling
5.7 This test method yields a pour point in a format similar
to Test Method D97/IP15 when the 3 °C interval results are 8.1 Obtain a sample in accordance with Practice D4057 or
D4177.
reported.
5.8 This test method has better repeatability and reproduc- 8.2 At least 1 mL of sample is required for each test.
ibility relative to Test Method D97/IP15 as measured in the
8.3 Samples of very viscous materials can be warmed until
2011 interlaboratory test program (see 13.1.2).
they are reasonably fluid before they are transferred; however,
no sample shall be heated more than is absolutely necessary.
6. Apparatus (see Annex A1)
The sample shall not be heated and transferred into the test
6.1 Automatic No Flow Point Apparatus —The apparatus
specimen cup unless its temperature is 70 °C or lower.
consists of a microprocessor–controlled test specimen chamber
NOTE 2—In the event the sample has been heated above this
that is capable of heating and cooling the test specimen at
temperature, allow the sample to cool until its temperature is below 70 °C
required rate, measuring the pressure inside the test specimen
before transferring it.
vial, and recording the temperature of the test specimen
8.4 Forsomesampletypes,suchasviscouslubeoilsthatare
chamber.Adetailed description of the apparatus is provided in
prone to having entrained air or gas bubbles present in the
Annex A1.
sample, the use of an ultrasonic bath (see 6.4) without the
6.2 The apparatus shall be equipped with a thermostatically
heater turned on (if so equipped), has been found effective in
controlled specimen chamber, digital display, cooling and
dissipating bubbles typically within 1 min.
heating systems, pressure measuring system, and a specimen
chamber temperature measuring device.
9. Preparation of Apparatus
6.3 The temperature measuring device in the specimen
9.1 Prepare the apparatus for operation in accordance with
chamber shall be capable of measuring the temperature from
the manufacturer’s instructions.
–105 °C to 60 °C at a resolution of 0.1 °C.
6.4 Ultrasonic Bath, Unheated—(optional), with an operat-
10. Calibration and Standardization
ing frequency between 25 kHz to 60 kHz and a typical power
10.1 Ensure that all of the manufacturer’s instructions for
output of ≤100 W, of suitable dimensions to hold container(s)
calibration of the mechanical and electronic systems and
operation of the apparatus are followed.
The sole source of supply of the apparatus known to the committee at this time
10.2 To verify the performance of the apparatus, a sample
is ISL model MPP 5Gs Analyzer, available from ISL, B.P. 70285 14653 Verson,
for which extensive data has been obtained by no flow point
France. If you are aware of alternative suppliers, please provide this information to
test method may be used. Such verification materials can also
ASTM International Headquarters. Your comments will receive careful consider-
ation at a meeting of the responsible technical committee, which you may attend. be prepared from intra-company cross checks.
D7346 − 15 (2021)
11. Procedure temperature (see 11.3) is reached, the specimen chamber is
cooled at a rate of 10 °C⁄min 6 1 °C⁄min until 30 °C warmer
11.1 Draw 0.5 mL 6 0.1 mL of sample into a micropipette
than the programmed expected no flow point, then the cooling
and transfer the specimen into a new clean, dry specimen vial.
rate is adjusted to 1.5 °C⁄min 6 0.15 °C⁄min and the no flow
When necessary, heat the sample in a water bath or oven until
point temperature is detected as described in 11.5.
it is just sufficiently fluid to transfer. Samples with an expected
no flow point above 25 °C or which appear solid at room 11.8 When reporting of the pour point is desired, round the
no flow point temperature in 11.5 to the next warmer 1 °C
temperature can be heated above 45 °C but shall not be heated
above 70 °C (see Note 2). interval or 3 °C interval, as specified, and record. Some
apparatus are capable of performing this automatically.
NOTE 3—Some samples like residual fuels, black oils, and cylinder
stock have been known to be sensitive to thermal history. In the case
12. Report
where such sample is tested, refer to Test Method D97 for sample
12.1 Report the temperature recorded in 11.5 with resolu-
treatment prior testing.
tion of 0.1 °C, as the no-flow point in accordance with Test
11.2 Place a new clean, dry specimen vial stopper on the
Method D7346.
specimen vial and insert the assembly into the apparatus. Start
the operation of the apparatus according to the manufacturer’s 12.2 Report the temperature recorded in 11.8 as the pour
point at either the 1 °C interval or 3 °C interval as specified in
instructions. When the expected no flow point of the specimen
is known, program it in the apparatus as EP (expected point) accordance with Test Method D7346.
and start test sequence. From this point up to and including the
13. Precision and Bias
terminationofthetest,recordingandreportingoftheresult,the
apparatus automatically controls the procedure. 13.1 Precision—The precision of this test method as deter-
mined by the statistical examination of the interlaboratory test
11.3 The apparatus adjusts the specimen chamber to a
results is as follows:
preselected starting temperature. By default, the preselected
13.1.1 No Flow Point:
starting temperature is 25 °C. Alternatively, the operator can
13.1.1.1 Repeatability—The difference between two results
preprogram a defined starting temperature between 25 °C and
obtained by the same operator with the same apparatus under
60 °C, if desired. When the expected no flow point is known
constant operating conditions on identical test material would,
and programmed in the apparatus, the starting temperature
in the long run, in the normal and correct operation of this test
shall be at least 30 °C warmer. In the event that the preselected
method, exceed the following only in one case in twenty.
starting temperature is programmed lower than 30 °C above
1.93 °C Range: –77 °C to +2 °C
the expected no flow point, the apparatus shall heat the
13.1.1.2 Reproducibility—The difference between two
specimen chamber to a starting temperature at least 30 °C
single and independent results obtained by different operators
above the expected no flow point, but not more than 60 °C.
working in different laboratories on identical test material
11.4 Whentheexpectednoflowpointofthespecimenisnot
would, in the long run, in the normal and correct operation of
known, once the starting temperature is reached (see 11.3) the
this test method, exceed the following only in one case in
specimen chamber is cooled at a rate of 1.5 °C⁄min 6
twenty.
0.15 °C⁄min.
2.62 °C Range: –77 °C to +2 °C
11.5 At the same time the cooling begins, the pressure
13.1.2 Pour Point at 3 °C Intervals:
measurement system is engaged to continuously monitor
13.1.2.1 Repeatability—The difference between two results
specimenbehavior.Whenadecreaseinpressure,asdetermined
obtained by the same operator with the same apparatus under
by the apparatus, is measured in the specimen vial, which
constant operating conditions on identical test material would,
signifies that the test specimen has ceased to flow due to a
in the long run, in the normal and correct operation of this test
crystal structure formation in the specimen or its viscosity
method, exceed the following only in one case in twenty.
increase, or both, the temperature of the specimen chamber is
0.0384 ~50 2 X! range:258 to112 (1)
recorded as the no flow point and held on a digital display.The
test chamb
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